Conducting A Quick And Easy Functional Lower Extremity Exam Of An Athlete

The art of doing a musculoskeletal exam on an athlete is really about utilizing simple tests in order to provide insights into the highly complex nature of human movement. There are many perspectives and philosophies on how to best examine the lower extremity.

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As podiatrists, we often look at things from the ground up and combine static exams like joint range of motion (ROM) and manual muscle testing with a dynamic (or functional) walking or running exam. Our training and license obviously focus on the structures distal to the knee, but if we do not examine and appreciate the influence of the proximal structures and the complexities of neuromuscular coordination or assess the patient in static and dynamic conditions, we are not being thorough enough.

The static and functional components of the exam are equally important and complementary in terms of the information they provide about the patient. The static exam is useful for assessing range of motion, deep tendon reflexes and muscle strength. The static exam includes closed chain and open chain tests, which isolate segments while they are unloaded or loaded. The dynamic exam is useful for assessing functional range of motion, neuromuscular coordination and muscle endurance. The dynamic exam allows us to assess the segments as they work together in a system under loading.

Given that most podiatrists are well versed in static tests of the lower extremity and gait examinations, let us take a closer look at quick, useful dynamic tests that one can easily add to a normal assessment without dramatically increasing the time required. Some of the tests are purposely redundant and allow us to pick up on subtle movement deficits. The tests do not require measurement tools but one can score or even videotape them to assess in more detail or review with the patient as needed.

Why Perform Functional Tests?

One of the most interesting aspects of the dynamic exam is that patients can often feel their deficit before the examiner points it out to them. This is very useful in that it helps them understand the underlying issues that may be contributing to their injury and also helps them buy into and comply with the treatment plan. Another benefit is that because the tests are so simple, many patients will test and retest themselves to monitor their own progress during treatment. This can serve as its own positive feedback loop to reinforce healthy behaviors.

An additional benefit of functional testing is that it allows for better communication and more detailed physical therapy and certified athletic trainer referrals. Our physical therapy colleagues appreciate and often are pleasantly surprised when we offer detail about deficits we have identified in clinic prior to the referral. A skilled physical therapist is an important part of the athlete’s treatment team and it is important to send patients to someone who is trusted and can provide the training necessary to help the athlete.

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As a disclaimer, the exercises to follow are by no means the only functional tests to consider and there are variations of each of these tests. As with all aspects of practice, clinicians should utilize the exam techniques that best mesh with their experience, practice philosophies and the unique needs of any given patient.

In the functional tests, we are looking for three things: symmetry, mobility and stability. As we often do with other exam techniques, we start looking very generally at the overall picture and then gradually focus our exam based on our findings and the patient’s chief complaint.

Functional movements require a strong and balanced core. It is well documented that weakness of the muscles of the low back, pelvis and proximal femur are a significant causative factor in spine, hip and patellofemoral injuries.1 There is also evidence that improved core strength affects rearfoot eversion and rearfoot eversion velocity.2

Testing core strength endurance is also important because many athletes may demonstrate adequate core strength in clinic but develop weakness or imbalances as they fatigue during activity. It is often surprising to find that even highly trained athletes can demonstrate core weakness.

A Guide To Tests For Core Stability

Single leg squat test. The patient stands with his or her hands on the hips or at the sides, transfers weight to one leg, extends the knee of the non-weightbearing leg with the non-weightbearing foot anterior to the body and bends the weightbearing knee until the knee is over the forefoot. The patient holds the position for 10 seconds while the non-weightbearing foot remains off the floor. The patient does this test with both legs.
Look for a smooth, coordinated movement, stable balance, level hips and shoulders, and the patella tracking over the second metatarsophalangeal joint. Obvious signs of deficits include: poor coordination of movement, flailing arms, shoulder and/or hip drop, a forward leaning torso and a medially deviating knee.2,3

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Planks. In the first position, the patient lies prone on the exam table or floor, and then raises his or her body to support weight with only toes, elbows and forearms. In the second position, the patient lies on the side and then raises the body to support his or her weight with only the lateral aspect of the bottom foot and the elbow. Test the side plank on both the left and the right. The patient should be able to hold each position for a minimum of 30 seconds.4

Look for proper alignment of the body from the feet through the cervical spine as well as a stable hold of the test with minimal shaking. Obvious signs of deficits include: complete inability to perform the action, tendencies to elevate or drop the pelvic area from the proper alignment and rotational inequalities in the pelvis.

Physical therapist Jay Dicharry often says “The test becomes the exercise” in instances when athletes demonstrate poor function.5 For example, athletes with poor core endurance would do plank exercises as part of their therapy.

How To Evaluate Balance And Proprioception

It goes without saying that balance is important in any weightbearing activity but as with core strength, there are a surprisingly significant number of our patients who will demonstrate significant deficits. Balance and proprioception issues increase the risks of ankle sprains.6 Fatigue and chronic ankle instability disrupt not just foot and ankle function, but also the dynamic postural control of the entire limb.7 In 2004, Malliou and colleagues found that proprioception training improved balance and reduced not just ankle sprains but overall injury rates in soccer players.8

Single leg balance test. Balance is of course important to all movement. Research has shown poor balance to increase the risk of injury to basketball players and proprioception training improves balance and reduces injury rates in young soccer players.6,8

The patient stands with his or her feet shoulder width apart. Then the patient transfers weight to one leg and balances on that leg while raising the non-weightbearing leg and bending the knee and hip 90 degrees. To add a dynamic component, the patient can swing the non-weightbearing leg in the sagittal plane. The patient should hold the position for 10 seconds with the eyes both open and closed.8

Key Insights On Ankle ROM Tests

As podiatrists, we are keenly aware that restricted ankle motion is a risk factor in both acute and overuse sports injuries.9-11

Differentiating between gastroc equinus and osseous equinus best occurs with a static exam and X-ray. One can quickly test functional ankle ROM with the lunge test, popularized by Bennel and coworkers.12 In this test, the patient stands with the toes 10 cm from a wall. Then flex the knee and dorsiflex the ankle to bring the knee as close to the wall as the patient can without lifting the heel. Measure the angle of the tibia in relation to the ground at a point 15 cm distal to the tibial tuberosity. Normal ankle ROM is 35 degrees or better.

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Another way to assess functional ankle ROM is with the deep squat. This test assesses not only the ankle but also the knees and hips for bilateral symmetric mobility.2 The patient stands with feet shoulder width apart and parallel to the sagittal plane. The patient then descends slowly into as deep of a squat as he or she can perform while keeping the heels on the floor, and his or her head and chest upright and facing forward. Observing from the front, the examiner looks for valgus collapse of the feet or knees and external rotation of the lower leg as signs of poor function. Observing from the side, the examiner sees if the thigh is parallel to the floor (or better) and/or if the butt is lower than the knees. Failure to get the butt low can indicate inadequate ROM.

Essential Pointers On Foot Intrinsic Muscle Strength/Activation

Manual muscle testing is an accepted part of the patient exam and provides information on the large extrinsic muscles of the foot and ankle complex. However, it is more difficult to isolate and test the smaller intrinsic muscles of the foot. Just as inhibition in activation of the gluteus medius muscle has been implicated in poor dynamic locomotor control of knee and hip, some speculate that inhibition of the intrinsic foot muscles may negatively affect gait and balance.13 Mann and Inman wrote that the intrinsic foot muscles “… play the principal active role in the stabilization of the foot during propulsion.”14 They also wrote that the pronated foot requires greater intrinsic muscle activity to stabilize the subtalar and midtarsal joints than does the normal foot. When running, the foot is in contact with the ground for 0.1 to 0.4 seconds. If there is any latency or inhibition of the intrinsic foot muscles, then the dynamic stability of the foot is compromised.

For the test, the patient stands evenly weighted with legs shoulder width apart. Then the patient presses the hallux to the ground while elevating and extending the lesser digits. If the flexor hallucis brevis is activated, the patient can do this movement quickly and in a smooth coordinated manner with no movement of the lower leg or rearfoot. If the muscle is inhibited, the patient will struggle, often everting the knee and rearfoot while recruiting the extrinsic muscles to compensate for the latency of the flexor hallucis brevis.15,16

For patients who do poorly with this test (and many do), “the test becomes the exercise.”5 Instruct the patient to do one set of 10 daily. Patients often report noticeable improvement with the coordination and activation of the flexor hallucis brevis after even a few days.

In Summary

One can easily incorporate these simple and quick tests into the physical exam and obtain a wealth of information. These tests can uncover hidden or subtle deficiencies such as proprioceptive deficits, muscle inhibitions and faulty movement patterns that are often present, even in fit, accomplished athletes. They are also very effective in helping athletes feel their own deficits and then monitor their response to therapeutic interventions.

Two excellent clinical resources that provide more depth to the physical exam and therapeutic interventions for the athlete are Jay Dicharry’s Anatomy For Runners: Unlocking Your Athletic Potential for Health, Speed and Injury Prevention and Gray Cook’s Movement: Functional Movement Systems, Screening-Assessment-Corrective Strategies.

Dr. Langer is in private practice at Twin Cities Orthopedics in Minneapolis. He is an Adjunct Clinical Professor at the University of Minnesota Medical School and a board member of the American Academy of Podiatric Sports Medicine.